Voter-backed bond money in hand, East County’s lone hospital is being prepped for major surgery.

The public agency that owns and leases out Grossmont Hospital in La Mesa is about to launch $225 million in improvements aimed at modernizing the hilltop medical complex and broadening patient services.

Construction is expected to begin early next year on several projects long on the Grossmont Healthcare District wish list, including renovation of the main patient building and the establishment of a heart and vascular center.

Money for the projects will come from a bond measure approved by district voters in 2006.

“From a health-care standpoint, these are very significant, especially being the lone hospital in East County,” said Barry Jantz, the district’s chief executive officer.

The improvements come at a time when many hospitals in San Diego County are as knee-deep in blueprints as X-rays.

UCSD opened a 76-bed cardiovascular center on its La Jolla campus in August and plans to open the 10-story Jacobs Medical Center in 2016. Scripps Health also wants to build a cardio complex in La Jolla and expects to start construction on the 168-bed facility in 2015.

Kaiser Permanente is looking at building a hospital in Scripps Ranch, while Palomar Pomerado Health is wrapping up construction on a nearly $1 billion hospital in Escondido.

Can the region support all these projects?

“That’s a fair question,” said Shawn Sheffield, chief strategy and business officer for UCSD Health Sciences. “Are we duplicating services? Do we need all these services?”

She said when it comes to cardiovascular centers, patient demand is rising, driven in part by the growth in the local elderly population.

At the same time, she expects some of the programs to fare better in the medical marketplace than others. “There are probably going to be some winners and losers,” she said.

Executives with Sharp HealthCare, which leases the 536-bed hospital from the Grossmont district, cite statistics that indicate a need for projects like the heart and vascular center.

According to figures compiled by the health-care industry, Sharp Grossmont handled at least 125 heart attack cases last year — more than any other hospital in California.

Michele Tarbet, chief executive officer of the La Mesa facility, attributed the high number in part to the large elderly population in East County, along with the limited medical options in the region.

The Grossmont district covers 750 square miles, stretching from the suburbs east of San Diego to rural communities like Campo and Pine Valley.

“Between us and Yuma there’s nothing,” Tarbet said.

Construction of the heart and vascular center is scheduled to start in March, with completion in 2014.

It will include three catheterization labs and a multipurpose room built to handle a range of procedures, including minimally invasive surgery and endovascular operations.

The project carries a price tag of $60 million — money that will come from Proposition G, the 2006 bond measure. The measure boosted property taxes in the district by an average of $40 a year.

An additional $44 million in bond funds will be spent to overhaul and update Grossmont’s 164-bed East Tower. The five-story structure was built in 1974.

New medical equipment fixtures will be installed in each room and the plumbing and lighting upgraded. Improved elevators will be installed.

Work on the project is expected to begin early next year and completed in 2014.

Other improvements soon to get under way include the construction of a $51 million, 18,000-square-foot central energy plant. New boilers, a steam generator and two emergency generators will be installed.

All the projects were outlined before the 2006 ballot measure. Voters also approved the creation of a citizens panel to oversee the improvements.

Ernie Ewin, the La Mesa councilman who chairs the panel, believes Grossmont district officials have so far lived up to the promises they made before the Prop. G vote.